Charging valve for pneumatic transport system

ABSTRACT

There is disclosed a drop gate valve on which material to be transported through a transport pipe is deposited so that when the gate is opened the material drops down through a valve housing built in-line with the transport pipe so that it drops into the transport pipe where it is carried through the pipe by air suction. A mechanically operated linkage mechanism is arranged to open the gate periodically and also to hold the gate in its closed position against the valve seat between the intermittent openings of the gate. A retaining ring is also provided in relation to the gate to control or retain the drain off of liquids which it is desired shall not freely drain off the valve body. This also provides a peripheral opening for the admission of air into the valve body each time the gate is opened.

Luiten et a1.

[ Nov. 20, 1973 1 CHARGING VALVE FOR PNEUMATIC TRANSPORT SYSTEM Inventors: Peter H. Luiten, Monrovia; John U.

Regus, West Covina, all of Calif.

Assignee: Aerojet-General Corporation, El

Monte, Calif.

Filed: Apr. 14, 1972 Appl. No.: 244,197

3,409,332 11/1968 Jones et al. 302/27 Primary ExaminerRichard E Aegerter Assistant Examiner-Hadd S. Lane Attorney-Edward O. Ansell et a1.

[57] ABSTRACT There is disclosed a drop gate valve on which material to be transported through a transport pipe is deposited so that when the gate is opened the material drops down through a, valve housing built in-line with the transport pipe so that it drops into the transport pipe (g1. I whe it is carried through the p p y air Suction A [58] Field 41 42 52 mechanically operated linkage mechanism is arranged 222/5O4 to open the gate periodically and also to hold the gate in its closed position against the valve seat between [56] Reierences Cited the intermittent openings of the gate. A retaining ring is also provided in relation to the gate to control or re- UNITED STATES PATENTS tain the drain off of liquids which it is desired shall not Goebels freely drain off the valve also provides a k peripheral opening for the admission of air into the .1 oore 1,938,942 712/1933 swam valve body each t1me the gate 1s opened. 2,019,502 11 1935 Osgood 222 504 11 Claims, 4 Drawing Figures 6 5 I 29 64 5 +466? 5: 47 k I I I 28 4/ I 4a: |i 77/145 4 I: Z6" t i ifl T' l Z5/ J 63 .55 o] 35 30/ 20a 6 56 45 LE: 0

CHfil-R'GINGVALVE FOR PNEUMATIC TRANSPORT SYSTEM I This invention relates to drop valves includingdrop valves of the so called in-line typewhereby material droppedthroughthe valve is received in a transport conduit through" which it is carried away.

It is a known practiceto transport material-from one place toanother' through a transportpipe or conduit to which-air suction is] applied which causes material introduced-into the conduit to be carried" through it'with the moving air and'deliveredto some desired place. Such transport conduits have been-usedfor'transporh ing various kindsof material; ordinarily. solids such as solid waste or refuse, solidlaundry or' other material to be sent-into'the pneumatic transport piping.

It" hasheretofore been known'to introduce-such material: into a transport conduit be depositing or dropping-lit into: a h'opper or the like leadingto a vertical standing member attached to. the channel byv suchmeansas a 'flange and bolt arrang'ement. Such asyst'em is shOWnih-TUS. Pat. N0. 3,3l6 ,026 issued: Apr. 25,

in accordance with the present invention disadvantages of prior known disposal=systems are overcome.

' The invention is carried outbyconnecting; the gravity;

chute to'a valve body which is joined tothetranspo'rt conduit; At the region wherethe delivery chute joins the valveabotly there: is provided-'axdrop valve'arrangement in the form;of a pivoted-gate on'which the material falling down-the chute rests until-the gate is-opened. Mechanism is providedfor opening the gate when'desired toallow the material to drop down-throughthe valve body into the transport conduit. Usually means will'be provided for-periodically opening the gate for a brief period.

A feature resides in the provision of-means'for con- I closed position it will not open even though the weight of'material dropped on it or the suction pressure in the transport conduitrnay be considerable, as the linkage mechanism provides a support which; prevents such opening until the linkage mechanism is operated to move it out of its supporting positionQ I The foregoing and other features ofthe invention will be better understood from the following detailed tie: scription and the accompanying drawing of WhiCllL,

FIG. I" shows a side elevationview. of a droplvalve connected with a transport conduit according to lthis invention, the valve being shown; in itsclosedposition; FIG. 2 is'across-sectional end ,view of the drop,valve and conduit arrangement of FIG I;

FIG. 3 shows the drop valve in its open position; and FIG. 4is a cross-section view at line 44 of 3. Referring to the drawing a valve housing 10 is joined to-the upper side of a horizontal transportconduit 11 under suction such that air flows through it in the direction of arrow 12 to carry with it material to be disposed of or delivered to a destination, ordinarily solids such as garbage, waste, laundry or other matter. The suction may be provided, for example, by a fan (not shown) locat'ed along the conduit to the left, with reference to FIGS. 1 and 3; The housing has a skirt section13 provided with side walls 14 and 15 which fits down over the sides of the conduit so that the lower edges of the housing skirt join the conduit approximately at the horizontal'diameter .16 of its cross-section. The forward wall 11 slants downwardly and forwardly in the directionfof" travel through the conduit, rnakingwan angle with-the vertical of about,6 0, for example. Therear wall=l8 isshown as slanting downwardly, and also forwardly at a somewhat lesser angle to the vertical but the inclination and direction of the rearwall-isnot critical, so long as the inclination of the forward andrear walls is such-as to give the material falling into the conduit a forward direction while'also preventing material from adhering to the forward wall. The conduit wall is openinto the housing at the area bounded by the housing skirt so that the falling material has complete freedom to enter into the pass through the conduit- The housing has a section 19 rectangular in shape in conformance with the top of the skirt section, attached above the skirt section 13 by afla nge 20 fastened to a corresponding flange 20a of the skirt section which may be done by bolts or the like, A shaft 21 passes through one of the side walls 22 and is journaled in bearings of bearingsupports 23 and 24 mounted to the cover 41 of section 19. A flat gate 25 attached to shaft 21' is-positioned to cooperate with the bottomof a ring contain liquid s which it is desired to prevent from spilling on-the valve-housing and on the surrounding building surfaces;

Another feature resides in provision'for admissionof air into the valvc'bocly when the gate valve is opened:

A further feature resides in the forming of the. valve body s'o that it isin-lin'e and in effect forms part-of the wall of the transport conduit at theposition ofthe valve and" has a: forwardly inclined wall arrangement which prevents until es ira'l'il'e adhering of material to the walls. I

further feature of the invention resides in a me- =chanical li'nlt age mechanism for opening the gate at times'whe'n it'is' to be opened. The arrangement of the linkage "isi'su'ch thatwhen the :gate is in its normally.

member 28, which is located concentrically around a gravity chute 27, leaving an annular space 29 between the chute and'the inner circumference of the ring. The lower end of the ring 28 is at the same level as the upper surface of the gate 25 (when the gate is closed) which forms an annular valve seat 26 for the bottom edge of the ring member. The gate 25 id adapted to be raised'by turning shaft 21 so that the gate seals against the lower surface of the ring 28 to close the bottom of the annular opening 29. The cover 41 meets the outer circumference of ther-ing so that the atmospheric air does not communicate with the interior of housing section 1.9 except through the annulus 29 when the gate is open. The ring istpreferably provided with a small hole through it for draining out liquid, as will be more fully explained hereinafter. The hole should preferably be dimensioned to be fitted with a plastic tubing or the like through which the liquid may be'conveyed to a desired receptacle if the amount of liquid exceeds the volume of space 29.

In FIG. 1 the gate is shown in its closed position. In FIG. 3 the gate is shown in its opened position which is done by turning the shaft 21. For the purpose of operating the shaft 21 to either the open or closed positions a crank is attached to the shaft and is operated by a powered cylinder 31 attached by a pivot 32 to a fixture 33 fastened to the housing. The cylinder contains a piston 42 having attached to it a rod 34 which operates the shaft 21' through a mechanical linkage comprising the crank 30 and linkage members 35 and 36 and fixtures 37 fixed to a support 38 attached to the conduit 11.

The arrangement of the linkage is such that when the gate is closed against the seat 26 in the horizontal position the linkage member 36 is vertical and substantially beneath the center of force of the loaded gate, which will be the longitudinal axis 39 of chute 27. The upper linkage member 35 is almost vertical with only a slight tilt toward the crank 30. The cylinder 31 and piston rod 34 are horizontal under this condition and the rod 34 is attached to linkage member 36 by a pivot 40.

Normally the mechanism is in the position shown in FIG. 1 with the gate closed. When in thisposition, the gate even when loaded can not be heavy enough to move the gate out of this position since the position of the linkage members 35 and 36 substantially beneath the center of force will not permit them to' deflect.-

Operation of the drop valve to open the gate and permit material resting above it to drop down through the valve body into the transport conduit is done by appli cation of pressurized fluid, normally compressed air, to the chamber 43 of the cylinder behind the piston while allowing pressure in chamber 44 to bleed out, to force the piston forward as shown in FIG. 3, causing the linkage to buckle and rotate the crank to open the gate. When it is desired to close the gate the fluid pressure will be removed from chamber 43 and allowed to bleed out, and instead applied into the forward chamber 44 of the cylinder, which will force the piston rearwardly to its position shown in FIG. 1.

Although it would be possible to perform this operation manually it is preferred to perform it intermittently by a timed mechanism. A suitable mechanism for doing this, shown in FIG. 1, comprises a valve cylinder 45 containing within it a disc valve 46 adapted to slide back and forth for a distance along its longitudinal axis. The cylinder has a centrally located entrance port 47 through its side wall and two exit ports 48 and 49 at opposite ends of the cylinder. A source 50 of compressed fluid, usually compressed air but optionally a hydraulic fluid, connects with the inlet port 47 through conduit 51. Exit port 48 connects with chamber 43 of cylinder 31 by a conduit 52 and exit port 49 communicates with chamber 44 through a conduit 53. The valve 46 is operated by a rod 54 which extends into a'solenoid 55 and is biased in the direction of arrow 56 by a compression spring 57 to maintain the valve normally in its position 46 which will apply pressure into chamber 44 to keep the gate in its closed position shown in FIG. 1. The solenoid is operated by a source of electrical power applied at terminals 58 and 59 over conductors 60 and 61 through a time switch 62 and through conductors 63 and 64 to the winding of the solenoid 55. When the gas electrical power is appliedonthe solenoidjtoperates the rod 54 in the direction opposite. arrow 56 against the compression of the spring to move the disc valve to the position 46a which has the, effect of removing the pressure from the forwardchamber 44 andapplying' it to the rear chamber 43 to move rod 34 forwardly and open the drop valve to the position shownfin FIG. 3.

Normally the electricalpower will, not b tappli ed to thesolenoid, hencethe. disc.valve,.will normally bein its position 46 which keeps the dropivalveiclose d. The

function of the .time switch is toapply ft heelectrical power from terminals 58 and 59 0 the enoid. The time switch may be of a well-know type adjusted to have the switch on for a period and off for a period of time. The on" period of the s wit ch should normally be for a very short timefsuch asa few seconds which. will be sufficient to allow all of the material which may have accumulated on top of the gate todrop down into the transport conduit, after which the time switch will open and remain open for a period of time until it again closes for a short time to open the gate again. The time switch may be adjusted so that the switch remains open for about 15 minutes, for example, and closed for a period of a few seconds. This intermittent opening of the drop valve at timed intervals will occur for as long as power is applied at terminals 58 and59.

It will be. recognized that other means than the valve cylinder, solenoid and timer arrangement may be used for operating the gate valve. e i

The operation of the system will be apparent'from the above description. When solid material is dropped into chute 27 it will be retained temporarily by gate 25 and then dropped at the proper time into the valve housing from where it will enter the transport pipe.

Since the valve housing is constructed in-line with the .transport pipe there will be no clinging of material to the walls of the valve body. Since the gate drops downwardly in opening there will be no clinging or wedging of material at the gate or its associated structure as can happen in the case of a laterally sliding gate. If liquids are dropped down chute 27 the liquid will accumulate in the annular region 29 because of the slight open space 66 between the bottom part of the wall of chute 27 and the top of the drop gate 26. This liquid will be drained off through hole 65, preferably through a suitable tube fitting into that hole, if it exceeds the volume of space 29.

Each time the gate is opened, the annular region 29 open to atmosphere at the top will now be open into the valve body, and because of the suction of the air travelling through the transport pipe, entrainment air will be drawn down to the transport pipe through the annular space 29, thereby facilitating and accelerating the flow of the solid material and retained liquid into the transport pipe.

The in-line valve according to this invention possesses many advantages over prior known valve designs, among which are: the elimination of the need for a separate transportpipe drop-tee fitting as is required to mount the usual slide type chute discharge valve; the assurance of a fail-safe operation since the gate remains closed under either electrical power interruption orcompressed airsupply failure; the possible jamming of the valve gate is eliminated; the in-line arrangement allows uninterrupted flow of air and material through the transport pipe even when the valve is open; the annular opening for the intake of entrainment air reduces the drawing of the system vacuum on the gravity chute itself; operational space is reduced compared to that required by the usual slide-type valve; and maintenance access is limited to one side of the valve body only.

The arrangement of the annular space 29 retains liquid waste and can divert it. This annular space arrangement is also useful if it be desired to adjust the amount of flow of entrainment air passing through it when the gate is open. This may be done by partially blocking the annular space.

What isclaimed is:

1. A charging valve for a pneumatic transport system comprising: a valve body containing a chamber adapted to communicate with a transport conduit which can be subjected to air suction, a pivot at an upper part of said chamber, a gate having a side attached to the pivot, material delivery chute means above said gate leading down to the top of the gate, a downwardly-facing valve seat at said delivery chute means above said gate, said gate being adapted to swing upwardly to seal against said valve seat, means operable to pivot said gate downwardly and out of sealing engagement with said valve seat, permitting material resting on the gate to drop down into said transport conduit, and to pivot the gate upwardly again to seal it against the valve seat, and an enclosure means encircling the bottom of the delivery chute means providing an annular space between the delivery chute means and the enclosure with the gate being adapted to seat against the lower edge of the enclosure means, said enclosure lower edge thereby providing the foregoing valve seat, whereby the valve body is sealed from the atmosphere.

2. A valve according to claim 1 in which the valve body is in-line with said transport conduit so that material flows through the transport conduit whether the gate is open or closed.

3. A valve according to claim 1 in which there is means for liquid communication between the interior of the delivery chute means and the annular space, in the vicinity above the gate when the gate is closed, whereby liquid dropping down the delivery chute means to the top of the gate passes into said annular space which retains it.

4. A valve according to claim 3 in which said means for liquid communication comprises a separation between the bottom edge of the delivery chute means and the gate when the gate is closed.

5. A valve according to claim 3 in which opening means is provided through the wall of said enclosure for drawing off excess liquid from said annular space to means of disposal.

6. A valve according to claim 5 in which the height of said opening means above the gate when the gate is closed determines the height to which liquid can rise in said annular space before draining off through said opening means.

7. A valve according to claim 1 in which the valve body has a forward wall slanting downward to the transport conduit in the direction of the air flow through the conduit.

8. A valve according to claim 1 in which the means operable to pivot the gate comprises a mechanical linkage positioned in a substantially vertical direction beneath the center of gravity of the gate to insure holding the gate closed.

9. A valve according to claim 9 in which the mechanical linkage is operated by a ram to open the gate.

10. A valve according to claim 9 in which the me chanical linkage is located at one side of the valve body.

11. A valve according to claim 10, in which the ram is operated at intermittent intervals to open and close the gate. 

1. A charging valve for a pneumatic transport system comprising: a valve body containing a chamber adapted to communicate with a transport conduit which can be subjected to air suction, a pivot at an upper part of said chamber, a gate having a side attached to the pivot, material delivery chute means above said gate leading down to the top of the gate, a downwardly-facing valve seat at said delivery chute means above said gate, said gate being adapted to swing upwardly to seal against said valve seat, means operable to pivot said gate downwardly and out of sealing engagement with said valve seat, permitting material resting on the gate to drop down into said transport conduit, and to pivot the gate upwardly again to seal it against the valve seat, and an enclosure means encircling the bottom of the delivery chute means providing an annular space between the delivery chute means and the enclosure with the gate being adapted to seat against the lower edge of the enclosure means, said enclosure lower edge thereby providing the foregoing valve seat, whereby the valve body is sealed from the atmosphere.
 2. A valve according to claim 1 in which the valve body is in-line with said transport conduit so that material flows through the transport conduit whether the gate is open or closed.
 3. A valve according to claim 1 in which there is means for liquid communication between the interior of the delivery chute means and the annular space, in the vicinity above the gate when the gate is closed, whereby liquid dropping down the delivery chute means to the top of the gate passes into said annular space which retains it.
 4. A valve according to claim 3 in which said means for liquid communication comprises a separation between the bottom edge of the delivery chute means and the gate when the gate is closed.
 5. A valve according to claim 3 in which opening means is provided through the wall of said enclosure for drawing off excess liquid from said annular space to means of disposal.
 6. A valve according to claim 5 in which the height of said opening means above the gate when the gate is closed determines the height to which liquid can rise in said annular space before draining off through said opening means.
 7. A valve according to claim 1 in which the valve body has a forward wall slanting downward to the transport conduit in the direction of the air flow through the conduit.
 8. A valve according to claim 1 in which the means operable to pivot the gate comprises a mechanical linkage positioned in a substantially vertical direction beneath the center of gravity of the gate to insure holding the gate closed.
 9. A valve according to claim 9 in which the mechanical linkage is operated by a ram to open the gate.
 10. A valve according to claim 9 in which the mechanical linkage is located at one side of the valve body.
 11. A valve according to claim 10 in which the ram is operated at intermittent intervals to open and close the gate. 